The prior art has evolved a variety of box structures, including wrapped boxes, simplex boxes, and foldable one-piece double-laminated sidewall boxes. "Wrapped" boxes are constructed by taping discrete segments of cardboard or stiff paper together at their corners to form a box, and then dressing the box by wrapping a relatively thin sheet of material around the box and gluing it in position. A "simplex" box is constructed by punching a box blank out of a sheet of stock and then folding the blank to form a box. The simplex box is held together by flaps which are tucked into and lockably engage mating slots provided in the box blank. "Double-laminated sidewall" boxes are also constructed by punching a box blank out of a sheet of stock and then folding the blank to form a box. The double-laminated sidewall box is glued together.
Double-laminated sidewall boxes are preferable to wrapped or simplex boxes because they are stronger and lend themselves to inexpensive, high-speed fabrication. Some problems have however been encountered in high speed fabrication of double-laminated sidewall boxes. For example, when the box side flaps are raised into position, they sometimes catch the adjacent box sidewall members, disrupting the high-speed box fabrication process. The mandrel against which the sidewalls are folded to form the box can also become stuck to the pre-glued box surfaces, which also disrupts the high-speed box fabrication process. The present invention overcomes these disadvantages, while providing a stronger box structure.